In this episode of Stuff You Should Know, the hosts examine the 1982 Tylenol murders, when several Chicago-area residents died after taking cyanide-laced Extra Strength Tylenol capsules. The summary covers the sequence of deaths that led to the discovery of product tampering, including how medical examiners identified lethal doses of potassium cyanide in the medication.
The hosts detail how this crisis sparked widespread panic in Chicago, leading to emergency hotline floods and canceled Halloween celebrations. They explore the subsequent investigation by a task force of local and federal authorities, who developed the theory of a "mad poisoner" operating near Chicago. The investigation was further complicated by hundreds of copycat incidents across the country, and the case remains unsolved to this day.

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In September 1982, a series of mysterious deaths occurred across Chicago and its suburbs. The first victim was 12-year-old Mary Ann Kellerman, who died shortly after taking Extra Strength Tylenol for a sore throat. On the same day, Adam Janus died under similar circumstances, followed by the deaths of his brother Stanley and sister-in-law Teresa after they took Tylenol from Adam's medicine cabinet. As Chuck Bryant chronicles, the deaths spread across different Chicago suburbs, with all victims sharing one common factor: they had taken Extra Strength Tylenol.
Medical examiner Michael Schaffer discovered that the Tylenol capsules contained 65 milligrams of potassium cyanide, exceeding the lethal dose of 50 milligrams. The victims' symptoms aligned with cyanide poisoning, which prevents the body from utilizing oxygen, leading to rapid organ failure and death. The investigation revealed that the tampering likely occurred at the retail level, after the Tylenol left the factory.
Josh Clark notes that the crisis created widespread panic, particularly in Chicago. After Dr. Edmund Donohue, Cook County's Deputy Medical Examiner, warned the public to stop using Tylenol, thousands of worried citizens flooded emergency hotlines. Chuck Bryant points out that the incident received massive media coverage, with a poll showing that 90% of people were aware of the poisonings within a month. The panic was so severe that some communities even canceled Halloween celebrations due to fears of product tampering.
The investigation, conducted by a task force including local investigators, the FBI, Illinois State Police, and the FDA, faced significant challenges. The contaminated capsules came from different production plants but shared the same lot number, MC2880. Police and Johnson & Johnson ultimately settled on the theory of a "mad poisoner" operating within a 50-mile radius of Chicago, either tampering with purchased Tylenol at home or directly in stores. The case remains unsolved, complicated by 270 copycat incidents nationwide, 36 of which were confirmed as serious tamperings.
1-Page Summary
The tragic timeline of the Tylenol murders begins as several healthy individuals across Chicago and its suburbs succumb to sudden and mysterious deaths after taking Tylenol.
The first known casualty in these tragic events was Mary Ann Kellerman, a healthy 12-year-old from Chicago who attended Jane Addams Middle School. On the morning of September 29, 1982, she complained of a sore throat, took an extra-strength Tylenol, and soon after collapsed in the bathroom. Her father found her, and she tragically died swiftly, possibly even before reaching the hospital. The paramedics who attended to Mary logged her Tylenol intake, which later turned out to contain a deadly substance.
On the same day, another nearby resident, Adam Janus of Arlington Heights, also died under similarly abrupt circumstances after taking Tylenol. The shock and tragedy soon compounded when two more—Adam's brother Stanley Janus, 25, and his wife Teresa, 19—took Tylenol from Adam's medicine cabinet. Shortly after, Stanley collapsed and passed away, while Teresa also collapsed and managed to fight for her life a few more days before succumbing.
Chuck Bryant chronicled these events, indicating that the deadly inc ...
The Timeline and Victims of the Tylenol Murders
The shocking discovery of lethal potassium cyanide in Tylenol capsules has raised grave concerns and complicated the investigation due to the suspected retail-level tampering.
A medical examiner named Michael Schaffer tested the Tylenol capsules and found some contained 65 milligrams of potassium cyanide. This concentration is well over the lethal dose, which is 50 milligrams, implying serious danger to anyone who might ingest the tampered capsules.
The rapid collapses and agonizing deaths observed after ingesting the Tylenol are consistent with cyanide poisoning symptoms. Cyanide poisoning disrupts the body's ability to use oxygen by binding to a protein essential for oxygen utilization within cells. Even as affected individuals can still breathe, oxygen isn’t being absorbed by their body's organs. This results in rapid cell death and causes critical systems like the central nervous system and the lungs to shut down sequently. Victims often gasp for air but are unable to breathe effectively, and may exhibit symptoms such as foaming at the mouth and convulsing.
Tylenol Tampering and Cyanide Poisoning Discovery
The Tylenol deaths in Chicago had a profound impact on the country, causing widespread panic and leading to significant changes in public behavior and product safety measures.
Josh Clark asserts that the Tylenol crisis deeply affected the national psyche, with the city of Chicago experiencing a climate of fear and panic.
A press conference held by Dr. Edmund Donohue, Cook County's Deputy Chief Medical Examiner, initially sparked the panic. He advised the public to discontinue the use of Tylenol, a warning that undoubtedly alarmed those who had recently ingested the medication. The deaths' correlation with Tylenol was established within just a few hours on September 29th, accentuating a rapid and effective response by the medical examiners and authorities.
Authorities, including one who is likely an official, issued warnings regarding the perils of Tylenol consumption and made considerable efforts to recall the product from the Chicago area. In the wake of realizing that a young girl had succumbed to poisoning and connecting this to the other deaths, there was prompt communication suggesting an issue with Tylenol.
Fears about the safety of consumer products rose to such levels that entire towns opted to cancel Halloween celebrations, worrying about candy tampering, reminiscent of an urban legend. Such was the ...
Public Panic and Response to Tylenol Crisis
Investigations following the Tylenol poisonings faced serious challenges as they tried to find how the Tylenol was tampered with and who was behind the deadly actions.
Authorities, who initially treated the cases as separate incidents due to occurring in five different towns in the Chicago area, quickly consolidated the investigations into the Tylenol Task Force. This task force, comprising local investigators, the FBI, the Illinois State Police, and the FDA, and led by the Illinois District Attorney's Office, struggled to determine both the perpetrator and the method of tampering. The Tylenol capsules were found to be from the same lot number, MC2880, but they originated from different production plants, and further testing by Johnson & Johnson confirmed they were pure, indicating that tampering with these capsules did not occur at a manufacturing or distribution level.
The police dragnet within a roughly 50-mile radius revealed that some contaminated Tylenol was still on drugstore shelves. The fact that tainted Tylenol was sold in different retail stores such as Juul food stores and Walgreens, coupled with the fact that the capsules came from different production plants, ruled out the possibility of it being an issue at a single distribution center.
Given the evidence that the tampering did not occur at the factory or distribution level, the police and Johnson & Johnson settled on the theory that a "mad poisoner" was responsible for the poisonings. They surmised that someone local to the Chicago area had tampered with the Tylenol within a 50-mile radius, potentially in as little as approximately seven hours. The theory developed that this person either purchased a ...
The Police Investigation and "Mad Poisoner" Theory
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